Wide variations in care furnished to patients with similar conditions have raised questions concerning the appropriateness of that care. Recent studies have found much inappropriate care for some diseases. Better care could improve patient outcomes and reduce overall costs. For many diseases, however, optimal treatments are controversial. We propose to analyze variations in the care that physicians provide to patients with peripheral vascular disease (PVD). Rates of surgery and angioplasty for this common condition vary widely. The controversy about appropriate treatment of PVD involves technical issues, patient preferences, and specialty turf battles. We will use national Medicare data to study large area variations and Medicare Carrier data to study variations in Southern California. We will also build a model of the progress of PVD over time that tracks symptoms and mortality for each hypothetical patient and treatment strategy. The model will be founded on expert opinion, clinical literature, Medicare data, and our own surveys of patient symptoms and preferences. The model will be used to develop guidelines for treatment that will be disseminated through our group of local community physicians. We will also develop educational materials for patients that help them understand the consequences of their choices. Finally, we will use Medicare Carrier data and our own surveys to evaluate the effect of dissemination on treatment decisions. To achieve these ends, the proposed project will build an interdisciplinary assessment team composed of researchers from The Rand Corporation and practicing physicians from UCLA. This team will consist of specialists in PVD, other medical specialties, epidemiology, decision analysis, economics, statistics, research design, survey research, data management, research synthesis, psychology, and evaluation.